The present disclosure relates to a developing device and to an image forming apparatus incorporating the developing device.
In image forming apparatuses exploiting electrophotography, such as copiers and printers, a device is widely used that forms a toner image on a sheet by developing in a developing device an electrostatic latent image formed on the surface of a photosensitive drum as an image carrying member. Some developing devices adopt a method in which toner is supplied as it is consumed.
Here, a developing device is known that has a developer chamber for stirring and mixing toner, a stirring/conveying member arranged in the developer chamber, and a toner inlet provided in a top surface of the developer chamber. Toner is supplied via the toner inlet into the developer chamber by the action of gravity. The stirring/conveying member has, in a part thereof under the toner inlet, a region which exerts reduced conveying power. With this configuration, in the region of the stirring/conveying member which exerts reduced conveying power, a balance is kept between the pressure of the toner moving toward the toner inlet and the pressure of the toner supplied from the toner inlet, and thus toner is supplied automatically as it is consumed.